siox: bus-gpio: add missing MODULE_DESCRIPTION()

make allmodconfig && make W=1 C=1 reports:
WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/siox/siox-bus-gpio.o

Add the missing invocation of the MODULE_DESCRIPTION() macro.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de>
Link: https://lore.kernel.org/r/20240530-md-siox-bus-gpio-v1-1-6a2f943ac8ad@quicinc.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>